Ditleff's humanitarian contributions during World War II are related to two specific episodes: the evacuation of foreign diplomats and Jews from Warsaw, and the White Buses campaign to rescue Scandinavians in German concentration camps.
Evacuation from Warsaw During the spring of 1939, Ditleff established a transit station in Warsaw for Jewish refugees from Czechoslovakia that had been sent there through the sponsorship of
Nansenhjelpen. Ditleff arranged for the refugees to receive food, clothing, and transportation to
Gdynia, where they boarded ships bound for Norway. As German forces approached Warsaw during September 1939, the Polish government and general staff escaped the city; however, most of the foreign diplomatic corps and other foreign nationals remained. Ditleff, acting as the
doyen of the corps, tried early to hail German military authorities with a handheld radio to arrange an orderly evacuation. German airplanes tracked the transmission and
strafed the car, but he was eventually able to negotiate a 4-hour cease-fire to arrange the evacuation of 1,200 individuals. They left in a convoy consisting of two trucks and sedans. Ditleff himself drove one car for 48 hours until he fell asleep behind the wheel.
White Buses Ditleff had returned to Norway by the time Nazi Germany
invaded and
occupied Norway but was able to escape to
Sweden, where he joined the Norwegian legation there. Ditleff actively opposed the "stay put doctrine" of the Norwegian and Danish governments—the idea that it was safer to let Norwegian and Danish prisoners stay in German concentration camps until hostilities ended, or to evacuate them through dangerous areas—advocating instead trying to retrieve Norwegian and Danish citizens in German concentration camps. During November 1944, he proposed a plan to rescue these prisoners and finally prevailed in securing sponsorship for the
White Buses operation that rescued tens of thousands of prisoners during the last months of the war. To negotiate the rescue with the German authorities, he enlisted
Folke Bernadotte to act using the good offices of the
International Red Cross. Bernadotte subsequently initiated contact with
Heinrich Himmler to implement the plan, which ultimately resulted in the evacuation of tens of thousands of refugees. ==Honours==